Latch operated clutch



Sept. 18, 1951 A. N. NILSON ETAL 2,568,249

L'ATCH OPERATED CLUTCH Filed Nov. 1, 1946 2 Sheets-Sheet l Flt-3.6

B fuzhfi ww TORNEY Sept. 18, 1951 Filed Nov. 1, 1946 A. N. NILSON ETAL LATCH OPERATED CLUTCH 2 Sheets-She et 2 FIG-3.3

FIG. 2

INVENTORS ARTHUR N. NILSON ROLF A. THIENEMANN WALTER J. ZENNER TTORNEY Patented Sept. 18, 1951 LATCH OlERATED CLUTCH Arthur N. Nilson and Rolf A. Thienemann, Chicago, and Walter J. Zenner, Des Plaines, Ill., assignors to Teletype Corporation, Chicago, Ill., a corporation of Delaware Application November 1, 1946, Serial No. 707,176

, 15 Claims. 1

This invention relates to clutches and more particularly to a high speed clutch designed for use in start-stop telegraph systems.

It is desirable that clutches employed with start-stop telegraph apparatus be rapid and uniform in action and that no slippage occur between the clutch parts during rotation. Such requirements are necessary in order that synchronism be maintained between rotating transmitter and receiver distributors. For example, where a receiver selector magnet is operable in I conjunction with a receiver selector cam. sleeve,

it is advantageous to have a clutch meeting the above requirements so that once the sleeve is oriented with respect to incoming signals, the

relationship will be maintained constant. It is apparent that at high signal speeds these requirements are even more exacting.

Single revolution clutches of the friction type,

- using discs of felt material as clutching elements are commonly employed for controlling the operation of transmitter or receiver cam sleeves in start-stop telegraph systems, as exemplified by the patent of H. L. Krum, No. 1,595,472, dated August 10, 1926. While such clutches may be satisfactory from an operating standpoint at moderate speeds, at high speeds. because of the increased load on the clutch parts, excessive heating and wear is caused, particularly in the'rest position of the clutch.

The prime object of the invention is to provide an improved start-stop mechanism, constructed in a manner which insures a high degree of efliciency in operation.

Another object of the present invention is to provide a rapidly and uniformly acting startstp mechanism particularly designed for high speed operation.

Another object of the present invention is to provide a clutch wherein a relatively small initial operating force is greatly increased to enable the eifective engagement of the driving and driven elements of the clutch.

A further object of the invention is to provide Another object of the invention is to provide 'in a friction clutch, latching means which prevents relative movement of the driving and driven elements of the clutch during rotation.

. Other objects anad advantages of the invention will appear as the clutch is described in more detail. a

In attaining the objects of the present invention there is provided a driving drum whose inner periphery is engageable by spaced bearing surfaces of an expansible metallic friction shoe. Operation of the friction shoe is controlled by a clutch lever which is under spring tension in the rest position of the clutch. When the clutch is released the clutch lever is free to move under the spring tension and thereby cause an expansion of the friction shoe enabling its spaced bearing surfaces to engage securely the inner periphery of the drum.

A first multiplication of the initial force exerted by the clutch lever spring is achieved due to the leverage obtained from the length of the clutch lever. The first of two pairs of spaced bearing surfaces of the friction shoe are cut at such an angle that they engage the inner periphery of the drum with a wedging action. The force is thus again multiplied (due to the mechanical principle of the wedge) at this first pair of bearing surfaces, and a multiplied force is also transmitted through connecting webs of the friction shoe to a second pair of spaced bearing surfaces. The second pair of bearing surfaces are also cut at an angle which insures their engagement with the inner periphery of the drum with a wedging action, and consequently again the force is multiplied. It is thus seen that a relatively small initial force exerted by the spring is greatly multiplied.

In the rest position of the clutch, the metallic friction shoe is out of effective engagement with the inner periphery of the drum and exerts negligible drag. It should be further noted that the shoe expands only slightly and with this small movement builds up a high clutching force. There is thus a minimum of motion in the operation of the clutch which is an advantage for quick action. Further, the clutch lever is mounted on a floating pivot, providing a hearing which is antifriction in nature, thereby reducing friction loss of power. Means are also provided for latching up the clutch lever during rotation of the clutch to prevent relative movement between the friction shoe and the drum,

The invention also provides a modified form of friction shoe which is made up of two parts. When the clutch lever is released the parts of the shoe pivot outwardly in opposite directions to engage the driving drum. Otherwise, the two piece friction shoe works on the same principle as the one piece friction shoe.

The invention may be more readily understood by reference to the detailed description which will now be described in detailf'Niiineral 'II'J represents a driving shaft which for the purpose of this description will be presumed to' be constantly rotating. Attached to shaft in any suitable manner is a driving drum [2, and mounted adjacent thereto is a collar I3 v having a 'shoiilderportion "I '4" about which, but out of" contact with; is. positioned a"metallic friction shoe "f'l iFrictionshoe "l6,'"whi'chis in theform of a in'eta'llidfi'ame, includes four spacedbearing surffaces' I1, I8, "I 9;and" 2|, designed to engage the "inn'er peripheryZZofdrum |2.*"Ea'ch of the bear- "ing surfaces of the friction shoe 'IB'are cut at an'anglewhich'insures their engagement with the innerperipheryztofdrum I2 with a wedging "action.

Alongside of collar I3 is'placed a spacer washer "'23 against whi'chis mounted a collar 24; having 1a shoulder25 aboutwhich is placed a' clutch lever f'i21.""Clutch1ever 2'I includes'a-bentoverlug 28 ide'sig'ne'd to rest'partiallyin a notch 29 of friction shoe I 6' and a' bent "over lug 30which' is in abutftingfielation with'a surface tl of the friction shoel 6." Resting against collar 24- is a raisedann'ular portion'32 of a'cam-sleeve-33 carrying a series of cams 34 whichmay' be; forexam'plejcams associated witha-receiver selectorfi- Above the 'raised an'nula'rportiorr 32' of cam sleeve 33 is sup- "'ported"afriction shoe drive plate 36 having a ib'nt 'overflug Si -designed to' rest in a'notch 38 fof'th'e frictionshoe l6. Adjustably connected to plat ieby means ofscrew and slot connections "39" is a'clutch' driving plate 4i having a fixed re- 1 tionship-withpam sleeve -33 by reason'ofthe "*erigageinnt'offits depending-lug -42 in key way 4 3 of cam sleev'33.

a Extendingfibetween clutchlever H-and clutch 'drivihg'platefll 'isa spring 44- which in the rest "position'of 'the' clut'ch is distended. A't-this time the" free" end 'of lever 46 which is pivoted at 41 andnormally urgedin a counterclockwise direc- FftlorffFig. 3)"by "spring 4 8; rests against-'- projection "49of clutch driving'plate 4 I "This-prevents backi ng up of the clutch; v Also at this *timea pro- *jfe'ctioh 5| of armature lever 52' which is urged in a"clockwise direction by spring -53"- about the pivot llflis in a'pos'itionengaging prbjection =54of the clutch lever'2l. Thusjin the restpositionof the "gclutch; levers 46 and- 52function -to hold spring A4 'unde'r' tension. U

When selector-"magnet '56-becori1es-dc-energized upon receipt of a no current start impulse, l'spring' 53 pivots armature lever- 52 in a clockwise .d irecti'ou'moying its projec'ti'on'il out of the path of projectionli l' of clutch lever- 21. This enables thej'contraction of spring 44 and causes clutch "lverfflin a floating pivotal movement to IOCkgiIl ga e. counterclockwise direction to; press its lug 2 8 against notch 29 dfTriction"shoe"|6 and-further "causes'its projection 39 to"'press-against the-sur- Ia'ce 3lof fric'tion shoe l6. "Thi's'wedges-thebear- 4 ing surfaces I! and 2| securely against the inner periphery 22 of drum 12 in opposite directions. The friction shoe [6 is now spread slightly and the thin connecting webs 51 and 58 are moved in 5 opposite outward directions causing bearing surfaces l8 and l9 also to engage securely the inner periphery' 22 of drum l2' with a wed'ging action. Assuming now that spring 44" has a relatively small initial operating force, movement of the relative1y long clutch lever 2'! causes its lug 28 to 'press a'gainst notch 29 of friction shoe IS with an increased force due to leverage and similarly enables its 'lug tfl-to press against surface 3| "ofdriction'shoeflfi with an increased degree of force. The w'e'dging action of the first pair of bearing surfaces" I! and 2| against the inner pe- ":ripheryzz iof theidrum multiplies this increased force at their engaging points and also multiplies the force transmitted along each connecting web 57 and 58 of the friction shoe l6. As bearing surfaces" 8 and l 9 engage theinner *periphery ZZ of d'rimi' 2, thdfofc'es' transmitted along webs il and 58 again-are mul-tiplied causing the engage- --me'nt -0f-th-surfaces w and I9 '-with-" the inner Deriphery of the drum 'itrs snother:increased "force. "Further-, the dii ction of rotation of ilhe 1 parts is s'u'chthatth'e inner periphery 22' oF-the dr'uni' l2 tendsto fuither expahct the sli'oe';- ag'iin inc'rea'sing the force at the bearing' sui fafiees l1,

18, 1 mend 2|.

-In-'operati0n ofi the clutch; after 'clutch reve'i' z'l eiipands the"friction shoe l 6, there is a tendency {forthe clutch" lever to rebound -and oscillate.

*Since' this I oscillation might result f in relative movement between-the friction shoe -I 6 and driv- -ing dr umfl2. the:clutchqatching mechanism now to be describ'ed is provided in- -the invention.

When the clutch le'ven-fl pivots in a counter- 4 clockwise direction (asl viewed in Fig. 3) it lug which is' pivotedon the plate ll at Standmormally i urged in a counterclockwise: direction my: a

---spring--'B5. -This tlatches' theclutch lever- 21M120 1 the pla't l l 'and prevents rela'tive movement-be- 4 tween the" friction sh'oe' I 6 and the; drum I Z'Iduring rotation of .the clutch -parts.

' When-the-clutchmears' the end of a-revo'lution, selector' magnet- 56 isaatwthiS tiine -receivinge a marking or current 'impuls'e thereby =placingpro- 5O jection 5 l *ofearmature =lever 52= in the path of upwardly rextendingz :arm- 66- of latch lever' 63, causing it' to -pivotina clockwise directionflas 'VieWedin Fig 3 -therebyunlatching 'clutch-Ilever 21. Shortly thereafter sprojection '545ofclutch 5 leveri -'2 11: strikes: fprojectiom 5 I of :-=the. armature 1ever 52.'limitihgwfurtherimoveinent of lever fl. Clutch: plate 4 i however; continuesato moverunder momentum and lever 46 falls-'in back of-'pr0- cation '49 as it' strikes 'the rear :1 of projection -454 andr reboundsi slightly-,athereby; again= pla'cing spring l4 under tension=readyw1for the nexts op- -eration.

Fig. 6 shows ainouifiedwformiof: .tri'ctiomslioe 6'! which eper'ates in-a manner siinilar toifriction sli'oel 6 In this casezthe; shoexis mad'eiup of two parts, '68 and BSJ Which are 'corinected together by a spring 'lly ith'e enlwfunction oflwhich:isrlto hold Ithe parts 'liGgl-lthel in' the' clutch a ssefiibly. When Y shoe- 67 isi operated' by clutchfi lever r 21, -parts 68 and 9 p'ivot in opposite outwardiiiirections at-the==p'oint |4' '-to effectithei efigagement oi' the fridtion shoe fi with the drum lw Theprinci'ple of operatiorf is otherwise the' same as n'las described in connection with the -kperatiom of The pin and screw connections 39 are provided between plates 36' and 41' in order to-p'rovide an adjusting means for taking up wear on the friction shoe l6. Projection I2 isprovided on plate 36 and projections 13 are provided on plate 4| so that a tool may be inserted into theclutch to move plates 36 and 4| relative to each other tomake necessary adjustments.

It is understood that While the invention has been described as being particularly adaptable operating means forenabling said first and sec ond pair of surfaces to engage said driving means and effect rotation of said driven means with said driving means, said first pair of surfaces" being designed to engage said driving means with a force greater than the initial operating force, and means for multiplying said greater force at said first pair of bearing surfaces and for transmitting a multiplied force to said second pair of surfaces, said secondpair of surfaces being designed to again multiply the force transmitted from the first pair of bearing surfaces.

2. In a clutch, driving means, driven means including a first pair of wedging surfaces for engaging said driving means, a second pair'of wedging surfaces for engaging said driving means, and operating means for enabling the engagement of said first pair of wedging surfaces with said driving means and said first pair of wedging surfaces cooperating with said driving means for enabling the engagement of said second pair of wedging surfaces with said driving means to thereby effect rotary movement of said driven means withsaid driving means.

3. In a clutch, driving means including a drum, driven means including an expansible frame having a first and second pair of wedging members for engaging said drum, and operating means for transmitting a force to said frame for expanding said frame, said first pair of wedging members being designed to engage said drum with a force greater than the force transmitted by said operating'means and to transmit also a tomato said second pair of wedging members greater than the force transmitted by said operating means, said second pair of wedging members being designed to engage said drum with a force greater than the force transmitted from said first pair of wedging members. I I

4. In a clutch, driving means, driven ;means including a plurality of wedging members for engaging said driving means, operating means for providing a force against said wedging members for enabling their engagement with said driving means to effect rotary movement of said driven means with said driving means, at least one of said wedging members being designed to engage said driving means with a force greater than the force provided by said operating means and to transmit also a force to one other of said wedging members greater than that force provided by said operating means, said last mentioned wedging member being designed to engage said driving means with a force greater than the force transmitted from the wedging member cperabie b a force received from said operating means.

5. In a clutch, driving means including a drum,

' driven means including an expansible frame hav 'ing a first and second pair of wedging members for engaging said drum and an operating never for transmitting a force to said frame for ex panding said frame and thereby effecting rotation of said driven means with said driving means, said first pair of wedging members being designed to engage said drum with a force greater than the force transmitted by said operating lever and to transmit also a force to said second pair of wedging members greater than that force transmitted by said operating lever, said second pair of wedging members being designed to engage said drum with a force greater than the force transmitted from said first pair of wedging members.

6. In a clutch, driving means including a drum, driven means including a two part frame having a first and second pair of wedging members for engaging said drum, and operating means for transmitting a force to said frame for moving each of said parts of said frame in opposite directions, said first pair of wedging members being designed to engage said drum with a force greater than the force transmitted by said operating means and to transmit also a greater force to said second pair of wedging members, said second pair of wedging members being designed to engage said drum with a force greater than the force transmitted from said first pair of wedging members.

7. In a clutch, driving means including a drum, driven means including a two part frame having a first and second pair of wedging members for engaging said drum, and an operating lever for transmitting a force and thereby moving said parts of said frame in opposite directions, said first pair of wedging members being designed to engage said drum with a force greater thanthe force transmitted by said operatin lever and to transmit also a greater force to said second pair of wedgin members, said second pair of wedging members being designed to engage said drum with a force greater than the force transmitted from said first pair of wedging members.

8. In a clutch, driving means including a drum, driven means including an expansible frame hav ing a first and second pair of wedging members for engaging said drum, an operating lever for transmitting a force to said frame for expand ing said frame and thereby effecting rotation of driven means with said driving means, said first pair of wedging members being designed to engage said drum'with a force greater than the force transmitted by said operating lever and to transmit also a force to said second pair of wedging members greater than the force transmitted by said operating lever, said second pair of wedging members being designed to engage said drum with a force greater than the force transmitted from said first pair of wedging members, and means for latching said operating lever to said driven means to prevent relative movement between said driving and driven means during r0- tation.

9. In a clutch, driving means including a drum, driven means including a two part frame having a first and second pair of wedging members for engaging said drum, and an operating lever for transmitting a force to said frame for movin said parts of said frame in opposite directions, said first pair of wedging members being designed to saeeaaae 6 7 'ngage said drum'vvith a iorcezgreater thamthe force tra:rrsmitted by!saideoperating'lever andyto transmit' aisoa greater force to (said second-pair 'of 'wedging niembers, :"said" second pair rot wedging members being de'sign'edtcv engage said :drum with a 'force greater thantheforce transmitted --from'-' said first pair ofww'edging members; and meansf fbr' latching s "saidzoperating lever to: said driven me'ans to prevent relative movement-abetween-said drivinga'nd driven means during rotation.

--10.-=='I-n a clutch; 'd'rivingvmeans; driven'ri means ineliiding' a plurality of engaging surfaces, *and operating means for exerting aforcetoitherby e'nablesaid engaging suria'ce's to enga'ge said driving m'eans and 'efiect rotation ofsaid rdriven 'eansia 'first one ofsaid engagingsurfa'ees being i desig ned to engage is'aid driving 'meanswith a force greater than said force exerted byi'saiidsoperatm means and: to transmit f a force." greater the force exerted by s'aidioperating means to asecbnd one 'Qfsaid' engaging: surfaces; said secondone' of said en-gaging members being de- -signed to engage said driving 'means with a dorce g're'aterthan the" force transmitted fromsaid -firs't one 'of said engaging surfaces.

3 I 11-; In" a clutch; driving 'meansgdriven means in'cl-uding a'plurality'of' groups ofengaging members' for' engag-ing said driving'means; andaoperating means 'for exerting a force against said en- '-gaig'ingmembers for enabling said engaging niem- Y; 13ers to engagesaid drivingmeans to effect -ro- -'-tation of said' driven" means with saiddriving means, a first group of said plurality of groups-bf engag'ing" members 'engaging""said1:driving means -vv-ith a force greater than "the forceexerted by 'said opera'ting 'n'reans -and transmittin avi'orce to a; subsequent group of said pluralityof groups 'of engaging m'embers' greater-thanthe force -;exerted by "saidoperating "means: "said subsequent group of said' plurality of -"g'roups ofengaging members engaging said: driving "means witha force greater'than that received-' from said first grou of engaging members.

12. In a clutch, drive "meansydriven means; a I plurality of engaging 'meanson'said: drivemmeans for- "'en'gagingisaid drive means," and operating means for exerting a force against a 'firstrone of said engaging means, said firstengaging-means cooperating with said drivemeans-in awedging 'manner :to' multiply the force exerted-" 'by said "operating means, said first-engaging means: co-

operating with said' secondengaging means -wherebythe multiplied force istransmittedto -a'se'cond one ofsaid-engaging means.

13. In: a "c1utch,:drive means, drivenmeans,--- a :-p1ura1ityof' engaging members on said driven "means for engaging said drive means;- and oper- 'atingmeans 'for exerting a forcetowedge a first one of said eng'aging members againstsaid: drive -means; said first: engaging member cooperating with -s'aid' drive means upon-the Wedging there- 28 boi iagainstsaidxirive means tomultiplyethe-force aexertedxbysaidoperating means; said first-enga -ing member ==being further efiective: to transmit the multiplied forceitoa-second one of said en- 5 f'gagingr membersrsaid. second one of; said engagziingi'members being effective to l wedge; against ':said drive :means vvith said multipliedforce.

14. In a, c1utch, -:tdrivemeans,' driven-meansra piurality of' engaging means on-said driven means fbrirengagings said"rdrive' means;:=and operating means for-exerting-a force against a first, group of: saidengaging means, said first r group rof renasgaging means engaging-with-.- said drive "means a ewedging manner and:cooperating ltherewith 15.-e:toam1i1tiply thez force exerted :by said operating means, whereby said first group of engaging means transmits the multiplied-force towai -sec- .vond'group-of saidiengaging means,- said-.- second group of engaging means beingefiective toeni gagesaid drive means in a wedging manner with 1 said multiplied force.

- '15.-A friction clutch including a drivin member; avdriven" member, means associated (with "said driven member-and having afirst'group and a-secondwgroup of spaced bearing surfacesdor engaging'saidvdriving' member,- operating means "associated with said first mentioned means for enabling the engagement of-rsaid=firstgroup-of bearing surfaces with said driving member at one force, said first group ofibearing surfacesengaging said driving 'member in 1 a wedgingmanner "to imultiply the first force; said first group =of bearing surfaces: being effective to transmit --the mu1tip1ied-forcetorsaid second :group of bearing v surfaces to enable. said. secondgroup of 'bearing ---surfaces to engage said driving member' withl-an increased degree :of force means for restraining said ioperating-means from operation in the rest a' positionof said c1utch, -and means for -re1easing said-restrainin means-tothereby enable engage- --ment--. of -:allw'ofesaid *bearing surfaces withesaid driving memberand-- consequent rotation ot-the 'clutch.

V ARTHUR N; N'ILSON.

WALTER JFZENNER.

REFERENCES CITED The fo11owing references are of recordin rthe inlet-of this patent:

".UN'ITEDE STATES PATENTS 

